66427845697 has 32 divisors (see below), whose sum is σ = 70689518240. Its totient is φ = 62347345920.

The previous prime is 66427845689. The next prime is 66427845713. The reversal of 66427845697 is 79654872466.

It is a Cunningham number, because it is equal to 257736²+1.

It can be written as a sum of positive squares in 16 ways, for example, as 7890946561 + 58536899136 = 88831^2 + 241944^2 .

It is a cyclic number.

It is not a de Polignac number, because 66427845697 - 2³ = 66427845689 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66427845397) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 31797829 + ... + 31799917.

It is an arithmetic number, because the mean of its divisors is an integer number (2209047445).

Almost surely, 2^66427845697 is an apocalyptic number.

It is an amenable number.

66427845697 is a deficient number, since it is larger than the sum of its proper divisors (4261672543).

66427845697 is a wasteful number, since it uses less digits than its factorization.

66427845697 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2453.

The product of its digits is 121927680, while the sum is 64.

It can be divided in two parts, 6642784 and 5697, that added together give a triangular number (6648481 = T₃₆₄₆).

The spelling of 66427845697 in words is "sixty-six billion, four hundred twenty-seven million, eight hundred forty-five thousand, six hundred ninety-seven".